Development of antibiotic treatment algorithms based on local ecology and respiratory surveillance cultures to restrict the use of broad-spectrum antimicrobial drugs in the treatment of hospital-acquired pneumonia in the intensive care unit: a retrospective analysis

Abstract

IntroductionTimely administration of appropriate antibiotic therapy has been shown to improve outcome in hospital-acquired pneumonia (HAP). Empirical treatment guidelines tailored to local ecology have been advocated in antibiotic stewardship programs. We compared a local ecology based algorithm (LEBA) to a surveillance culture based algorithm (SCBA) in terms of appropriate coverage and spectrum of antimicrobial activity.MethodsWe retrospectively assessed 2 hypothetical empirical antibiotic treatment algorithms for HAP on an existing high-quality prospectively collected database in a mixed 36-bed tertiary intensive care unit (ICU). Data on consecutive episodes of microbiologically confirmed HAP were collected over a period of 40 months and divided in a derivation (1 July 2009 to 31 October 2010) and validation (1 November 2010 until 31 October 2012) cohort. On the derivation cohort we constructed a LEBA, based on overall observed bacterial resistance patterns, and a SCBA, which targeted therapy to surveillance culture (SC) in the individual patient. Therapy was directed against pathogens found in respiratory SC collected two to five days before HAP, and in the absence of these, presence or absence of multi-drug resistant (MDR) pathogens in other SC dictated broad-spectrum, respectively narrow spectrum antibiotic therapy. Subsequently, LEBA and SCBA were retrospectively reviewed and compared with actually prescribed antibiotics in the validation cohort.ResultsThe first 100 HAP episodes made up the derivation cohort and the subsequent 113 HAP episodes the validation cohort. Appropriate antibiotic coverage rates by applying LEBA and SCBA were 88.5% and 87.6%, respectively, and did not differ significantly with respect to appropriateness of the actually prescribed initial therapy (84.1%). SCBA proposed more narrow spectrum therapy as compared to LEBA and the actually prescribed antimicrobials (P <0.001). SCBA recommended significantly less combination therapy and carbapenems compared to LEBA (P <0.001). SCBA targeted antibiotics to recent respiratory SC in 38.1% (43 out of 113 episodes) of HAP; in these cases adequacy was 93% (40 out of 43).ConclusionRates of appropriate antimicrobial coverage were identical in LEBA and SCBA. However, in this setting of moderate MDR prevalence, the use of SCBA would result in a significant reduction of the use of broad-spectrum drugs and may be a preferential strategy when implementing antibiotic stewardship programs.

Respiratory infections in the Asia‐Pacific region: Problems and cautious optimism

“…As Rodrigo‐Troyano and Sibila point out, unlike tuberculosis, there has been very little progress in antibiotic development for MDR‐GNB and case reports are increasing for pan‐resistant organisms immune to all known therapies. While newer antibiotics are desperately needed, important factors that Rodrigo‐Troyano and Sibila did not focus on are the key role of effective antibiotic stewardship and appropriate end‐of‐life care in reducing the selective pressure for MDR pathogens.…”

Minimizing antibiotic exposure in the ICU: in search of the optimal strategy

“…The primary goal of active surveillance cultures (ASC) is to guide preventive strategies to avoid transmission of multidrug-resistant bacteria, by identifying carriers and implementing or maintaining isolation and contact precautions when indicated. ASC may also be used to predict infection with multidrug-resistant bacteria in septic patients and better tailor antimicrobial therapy, especially for ventilator-associated pneumonia (VAP), as suggested in a previous issue of Critical Care by a group of investigators in Ghent [ 1 ].…”

“…There are three distinctive features of this study [ 1 ]. First, the authors derived the prescription algorithms subsequently tested from a previous analysis of 100 episodes of pneumonia; although few details are provided on their construction, the algorithms were intended to provide >85% adequate antimicrobial coverage while avoiding overtreating patients with unnecessarily broad-spectrum antibiotics.…”

“…Applying ASC to pneumonia in nonventilated patients is of potential interest; however, the microbiologic features of HAP may differ from those of VAP, and obtaining ASC in these patients (especially respiratory tract cultures) is more difficult. Indeed, recent (2 to 5 days) respiratory tract samples to target therapy were available in 63 (56%) of all 113 episodes and were positive in 43 (38%) cases; these samples would have guided therapy in 31/52 (60%) episodes of VAP, but in only 12/61 (20%) episodes of HAP [ 1 ].…”

“…It is noteworthy that De Bus and colleagues found no difference in the appropriateness of therapy when comparing the two (theoretical) algorithm-based strategies with the actual therapy received by patients [ 1 ]. However, treating physicians were aware of the results of ASC and were probably influenced to some extent by them, given the longstanding tradition of using ASC at this center [ 3 , 7 , 9 ].…”